The phrase "add to the shipment" is correct and usable in written English.
You can use it when referring to including additional items or products in a shipment that is already being prepared or processed.
Example: "Please let me know if you would like to add to the shipment before it leaves the warehouse."
Alternatives: "include in the shipment" or "supplement the shipment".
That money is being added to the shipment of funds being flown from here tonight.
A postscript boasted that 79 cans of concentrated chicken "nicely soddered [sic] up" had been added to the shipment.
She said Beckwith doubled its tree shipments two years ago, when wreaths were added to the online choices.
A political crisis in neighboring Ivory Coast — which landlocked Burkina Faso depends on for food shipments — has forced up living costs, adding to the unrest.
Edit any information at this time Add to SCAN Form (Shipment Confirmation Acceptance Notice) Postal employee will scan this form as packages accepted.
You will also be able to choose free samples to add to your shipments from manufacturers.
Roadblocks slow the movement of goods; complex inspections of shipments add to processing costs; restricting entry to the United States of the 99.9999percentt of foreign citizens who mean no harm is bad for tourism, for movement of intellectual capital and other aspects of the economy.
A Pentagon official said in 2010 that Hezbollah's arsenal was believed to include a small number of Fateh-110s, and additional shipments would add to Hezbollah's striking power.
But the increase in orders this spring suggests shipments will rise in the July-September quarter and add to growth.
This went on for more than eight months, and it was only shortly before Akerlof himself returned home that he managed to solve his problem: another friend happened to be sending some things back to the U.S., and Akerlof was able to add Stiglitz's clothes to the shipment.
Add a return receipt to the shipment.
